Daniel A. Root wrote:

The differences between oneesama, oneesan, 
oneechan, nee-chan, <someone>-ane, and 
<someone>-onechan, are subtle, but can tell 
you a lot about the relationship to that 
person's older sister.  

Daniel,

Thanks for all your helpful commentary.  It's *very* enlightening.  I 
can't alienate my Japanese-literate readers by my poor use of Japanese.

<sigh> And I *so* wanted to keep the Japanese in there.

Maybe you can help.  What do *you* think Kasumi would call her sisters? 
 What would they call her?  I know that "Otoosan", "Okaasan", and 
"Ojisama" are correct; is there anything else that I use wrong?

As an aside, I agree with what someone else said; "Ranma no baka!" 
sounds *much* better than "Ranma, you jerk!".  :)

Thanks again, Daniel.

-Richard